(No Model.) N TESLA, ELECTRIC ARC LAMP, 2. Sheets-Sheet 1. No. 335,786, Patented Feb. 9, 1886, SA N Peters, photo-lithographer, washington,
(No Model.) 2. Sheets-Sheet 2. N TESLA. ELECTRICAR CLAMP, No. 335,786, Patented Feb. 9, 1886, %age artial : a. 2%i 2 Pred Sys 24 ovt. e/e7áz/- -/64-2744. N. PETERs, Photo-Lithographer, Washington, D.C. rt -2s 2d (24.
5 IC) 25 35 45 UNITED STATES PATENT OFFICE. NIKOLATESLA, OF SMILJAN LIKA, AUSTRIA-HUNGARY, ASSIGNOR TO THE TESLAELECTRIC LIGHT AND MANUFACTURING COMPANY, OF RAHWAY, NEWJERSEY. ELECRC-ARC AMP. SPECIFICATION forming part of Letters Patent No. 335,786, dated February 9, 1886. Application filed March 30, 1885. Serial No. 160,574. To all whon it may concern Be it known that I, NIKOLATESLA, of Smil jan Liika, border country of Austria-Hungary, have invented certain new and useful Im provements in Electric-Arc Lamps, of which the following is a specification. My invention relates more particularly to those arc lamps in which the separation and feed of the carbon electrodes or their equiva lents is accomplished by means of electro magnets or Solenoids in connection with suit able clutch-mechanism; and it is designed to remedy certain faults common to the greater part of the lamps heretofore made. The objects of my invention are to prevent the frequent vibrations of the movable elec trode and flickering of the light arising there from, to prevent the falling into contact of the electrodes, to dispense with the dash-pot, clock-work, or gearing and similar devices heretofore used, and to render the lamp ex tremely sensitive, and to feed the carbon al most imperceptibly, and thereby obtain a very steady and uniform light. In that class of lamps where the regulation of the arc is effected by forces acting in oppo sition on a free movable rod or lever directly connected with the electrode, all or some of the forces being dependent on the strength of the current, any change in the electrical con dition of the circuit causes a vibration and a corresponding flicker in the light, This dif ficulty is most apparent when there are only a few lamps in circuit. To lessen this diffi culty, lamps have been constructed in which the lever or armature, after the establishing of the arc, is kept in a fixed position and can not vibrate during the feed operation, the feed mechanism acting independently; but in these lamps, when a clamp is employed, it frequently occurs that the carbons come into contact and the light is momentarily extinguished, and, frequently, parts of the circuit are injured. In both these classes of lamps it has been gustom ary to use dash-pot, clock-work, or equiva lent retarding devices; but these are gener. ally unreliable and objectionable, and increase the cost of construction. (No model.) sired objects and to remedy the before-men tioned defects. I combine two electro-mag nets--one of low resistance in the main or lamp circuit, and the other of comparatively high resistance in a shunt around the arc-a. movable armature-lever, and a novel feed mechanism, the parts being arranged so that in the normal working position of the arma ture-lever the same is kept almost rigidly in one position, and is not effected even by con siderable changes in the electric circuit; but if the carbons fall into contact the armature will be actuated by the magnets So as to move the lever and start the arc, and hold the car bons until the arc lengthens and the arma ture-lever returns to the normal position. After this the carbon-rod holder is released by the action of the feed mechanism, so as to feed the carbon and restore the arc to its normal length. My invention consists, mainly, in the par ticular manner in which the armature is com bined with the magnets and acted upon by them and in the feed-controlling mechanism. In the drawings, Figure 1 is an elevation of the mechanism made use of in the electric lamp. Fig. 2 is a plan view of the same be low the line a (c. Fig. 3 is an elevation of the balancing lever and spring, and Fig. 4 is a de tached plan view of the pole-pieces and arma tures upon the friction-clamp, and Fig. 5 is a section of the clamping-tube. M is a helix of coarse wire in a circuit from the lower-carbon holder to the negative bindo ing-screw -e. N is a helix of fine wire in a shunt between the positive binding screw -- and the negative binding-screw -. The upper-carbon holder S is a parallel rod sliding through the plates S' S of the frame of the lamp, and hence the electric current passes from the positive bind ing-post -- through the plate S, carbon holder S, and upper carbon to the lower car bon, and thence by the holder and a metallic connection to the helix M. The carbon-holders are of any desired char 95 acter, and to insure electric connections the springs l are made use of to grasp the upper My invention is intended to effect the de- carbon holding rod S, but to allow the rod to SO 55, 75 So
O 25 35 45 55 335,786 slide freely through the same. These springs the core M'. If, now, the are becomes too l may be adjusted in their pressure by the long, the current through the helix M is less Screw m, and the spring l may be sustained sened, and the magnetism of the core N is in upon any suitable support. I have shown creased by the greater current passing through them as connected with the upper end of the the shunt, and this core N attracting the seg core of the magnet N. mental armature r lessens the hold of the Around the carbon-holding rod S, between clamp R. upon the rods, allowing the latter to the plates SS, there is a tube, R, which forms slide and lessen the length of the are, which a clamp. This tube is counterbored, as seen in the section Fig. 5, so that it bears upon the rod Satits upper end and near the middle, and at the lower end of this tubular clamp R there arearmature-segments r of soft iron. A frame or arm, n, extending, preferably, from the core N, supports the lever A by a fulcrum-pin, 0. This lever A has a hole, through which the upper end of the tubular clampr passes freely, and from the lever A is a link, q, to the lever t, which lever is pivoted at y to a ring upon One of the columns S. This lever t has an opening or bow surrounding the tubular clamp R, and there are pins or pivotal connections w between the lever t and this clamp R, and a spring,, serves to support or suspend the weight of the parts and balance the same, or nearly so. This spring is preferably adjust. able. At one end of the lever A is a soft-iron arma ture block, a, over the core M of the helix M, and there is preferably a limiting-screw, c, passing through this armature-blocka, and at the other end of the lever Alis a soft-iron arma ture-block, b, with the end tapering or wedge shaped, and the same comes close to and in line with the lateral projection e on the core N. The lower ends of the cores M N are made with lateral projecting pole-pieces M: N, respectively, and these pole-pieces are con cave at their outer ends, and are at opposite sides of the armature-segments r at the lower end of the tubular clamp R. The Operation of these devices is as follows: In the condition of inaction the upper carbon instantly restores the magnetic equilibrium and causes the clamp R to hold the rod S. If it happens that the carbons fall into contact, then the magnetism of N is lessened so much that the attraction of the magnet M will be sufficient to move the armature a and lever A so that the armature b passes above the nor mal position, so as to separate the carbons in stantly; but when the carbons burn away a greater amount of current will pass through the shunt until the attraction of the core N' will overcome the attraction of the core M and bring the armature-lever Aagain into the nor mal horizontal position, and this occurs before the feed can take place. The segmental arma ture pieces rare shown as nearly semicircular. They may be square or of any other desired shape, the ends of the pole-pieces MN being made to correspond in shape. I claim as my invention 1. The combination, in an electric-arc lamp, of the electro-magnets in the main and shunt circuits, respectively, an armature-lever and connection to the movable carbon-holder, the core of the shunt-magnet passing across the end of the armature-lever, substantially as set forth, so that the two magnets act in conjunc tion on the armature-lever in moving the car bon to form the arc and in opposition to each other beyond the normal position of the arma ture-lever, substantially as specified. 2. The combination, with the carbon-hold ers, of two magnets, one in the main circuit and the other in a shunt-circuit, and an arma ture-lever to draw the arc, and a feeding rests. upon the lower one, and when the cur mechanism and pole-pieces upon the electro rent is turned on the electricity passes freely, magnets to act upon the feeding mechanism, by the frame and spring l, through the rod S substantially as specified. and carbons to the coarse wire and helix M, 3. The combination, with the carbon-hold and to the negative binding-post W, and the ers, of two magnets, one in the main circuit core M thereby is energized. The pole-piece and the other in a shunt-circuit, and an arma Mattracts the armaturer, and by the lateral ture-lever between two poles of such electro pressure causes the clamp R to grasp the rod magnets to draw the arc, and a feeding mech S, and the lever A is simultaneously moved anism and pole-pieces upon the other two from the position shown by dotted lines, Fig. oles of the electro-magnets to act upon the 1, to the normal position shown in full lines, feeding mechanism, substantially as specified. and in so doing the linkg and levert are raised, 4. The combination, with the carbon-hold lifting the clamp R and rod S, separating the ing rod in an electric-arc lamp, of the clamp carbons and forming the arc. The magnetism R, levert, spring ", armature-lever A, and of the pole-piece e tends to hold the lever A electro-magnets M N in the main and shunt level, or nearly so, the core N being energized circuits, respectively, the pole-pieces MN, by the current in the shunt which contains and armature-segments, substantially as set the helix N. In this position the lever A is forth. not moved by Ordinary variation in the elec 5. The combination, with the carbon-holder, tric current because the armature b is strongly of a tubular clamp surrounding the same, an attracted by the magnetism of e, and these parts armature - lever connected to said tubular are close to each other, and the magnetism of clamp, and electro-magnets in the main and e acts at right angles to the magnetism of shunt circuits,respectively, and armature-seg 75 IOO IO5 IIO II5 125
335,786 3. ments upon the tubular clamp adjacent to the into action or releasing it, substantially asset Io lateral poles of the electro-magnets, substan- forth. tially as set forth. Signed by me this 25th day of March, A. 6. In an electric-arc lamp, the combination, D. 1885, 5. With the carbon-holding rod, of a clamp, two armatures upon the clamp, and electro-mag nets in the main and shunt circuits, respectively, the poles of which act upon the armatures of the clamp for bringing the same Witnesses: GEO. T. PINCKNEY, CHAS. H. SMITH. NIKOLA TESTA.